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Objective To investigate the combined effect and mechanism of metformin (Met) and 2-deoxy-D-glucose (2DG) on cell proliferation and apoptosis in liver cancer cells HepG2 and Hep3B.Methods Wst-1 reagent was used to determine the anti-proliferation effects after treatments with Met and 2DG alone or combined in HepG2 and Hep3B cells.Microscopy was used to observe cell morphological changes after treatments with Met and 2DG alone or combined in HepG2 and Hep3B cells.Cell apoptosis was observed by flow cytometry after treatment of different kinds of drugs.Western blotting was used to analyze the protein expressions of Caspase-3,PARP,Mcl-1 of HepG2.Results The survival rate of HepG2 cells in the combination group was (22.48 ± 0.51)％,and compared with the control group (100.00 ± 5.05)％,Met group (80.68 ±5.10)％ and 2DG group (72.56 ±4.34)％,the differences were statistically significant (P ＜ 0.001;P ＜ 0.001;P =0.001).The survival rate of Hep3B cells in the combination group was (29.16 ± 1.34) ％,and compared with the control group (100.00 ± 1.23) ％,Met group (59.58 ± 1.92) ％ and 2DG group (33.87 ± 1.95) ％,the differences were statistically significant (P ＜ 0.001;P ＜ 0.001;P =0.001).Microscopy observation showed that combined treatment of Met and 2DG caused less viable adherent cells of HepG2,but more floating dead cells.While the combination group also caused a decrease in the density of Hep3B cells,but did not significantly increase the shedding of cells.The apoptosis of HepG2 cells in the combination group was (39.63 ± 0.21) ％,and compared with the control group (7.12 ± 0.14) ％,Met group (12.56 ± 0.35) ％ and 2DG group (15.16 ± 1.93) ％,the differences were statistically significant (P ＜0.001;P ＜ 0.001;P =0.001).The apoptosis of Hep3B cells in the combination group was (12.58 ± 1.03) ％,and compared with the control group (2.82 ± 0.51) ％ and Met group (8.98 ± 0.86) ％,the differences were statistically significant (P ＜ 0.001;P =0.007),but compared with the 2DG group (12.40 ± 1.78) ％,the difference was not statistically significant (P =1.000).Furthermore,Western blotting demonstrated that the combined treatment induced evident Caspase-3 activation and poly ADP-ribose polymerase (PARP) cleavages,and decreased expression of Mcl-1.Conclusion The combination of Met and 2DG can effectively inhibit cell proliferation of HepG2 and Hep3B,and induce apoptosis of HepG2 cells.The mechanism may be involved with Caspase-3 activation,cutting PARP substrate and decreasing Mcl-1 protein.
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Cystic echinococcosis (CE) treatment urgently requires a novel drug. The p38 mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases, but still have to be characterized in Echinococcus granulosus. We identified a 1,107 bp cDNA encoding a 368 amino acid MAPK protein (Egp38) in E. granulosus. Egp38 exhibits 2 distinguishing features of p38-like kinases: a highly conserved T-X-Y motif and an activation loop segment. Structural homology modeling indicated a conserved structure among Egp38, EmMPK2, and H. sapiens p38α, implying a common binding mechanism for the ligand domain and downstream signal transduction processing similar to that described for p38α. Egp38 and its phosphorylated form are expressed in the E. granulosus larval stages vesicle and protoscolices during intermediate host infection of an intermediate host. Treatment of in vitro cultivated protoscolices with the p38-MAPK inhibitor ML3403 effectively suppressed Egp38 activity and led to significant protoscolices death within 5 days. Treatment of in vitro-cultivated protoscolices with TGF-β1 effectively induced Egp38 phosphorylation. In summary, the MAPK, Egp38, was identified in E. granulosus, as an anti-CE drug target and participates in the interplay between the host and E. granulosus via human TGF-β1.
Subject(s)
Humans , Cloning, Molecular , DNA, Complementary , Echinococcosis , Echinococcus granulosus , Echinococcus , In Vitro Techniques , p38 Mitogen-Activated Protein Kinases , Phosphorylation , Phosphotransferases , Protein Kinases , Signal TransductionABSTRACT
Objective To explore the relationship between polymorphism of catechol-O-methyltransferase (COMT) gene valine (Val) 158 methionine (Met) (G to A transition)and the distribution in population and esophageal squamous cell carcinoma (ESCC) in Yili prefecture of Xinjiang.Methods A hospital based case-control study was adopted, a total of 622 subjects, which including 214 ESCC patients and 408 age, gender and ethnicity-matched normal control individuals.The polymorphism of COMT gene G to A transition was analyzed with PCR-restriction fragment length polymorphism approaches.Results The COMT genotype frequencies in 622 subjects in Yili prefecture were GG genotype accounted for 47.3%, GA type for 42.3% and AA type for 10.4%, G allele was 68.4% and A allele was 31.6%.There was no statistical difference in the COMT genotype and frequencies of allele distribution between ESCC group and control group.Furthermore, stratified analysis indicated that there was statistical difference between ESCC group and control group in subjects less than 60 years old.There was statistical difference in the allele distribution among Kazak,Uygur and Han ESCC groups.The COMT genotype and frequency of allele distribution among normal control groups of the three ethnic groups were statistically different.After corrected age and gender,there was no statistical difference in COMT Val158Met polymorphisms among Kazakh, Uygur and Han ethnic groups in both ESCC and control groups in Yili Prefecture of Xinjiang.Conclusion COMT gene Val158Met single nucleotide polymorphism may not be the genetic markers of ESCC risk in Yili Prefecture of Xinjiang.
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Objective To estimate the effect of microRNA (miRNA) let-7 expression on human esophageal squamous cell carcinoma(ESCC) and the relationship between let-7 level and clinicopathological parameters. Methods ESCC cell line (Eca109) was transfected with let-7 or its inhibitor by RNAi and cell transfection techniques. Normal cultured Eca109 cell was served as negative control. The proliferation of Eca109 cell was detected by MTT. The expression of let-7 in Eca109 cells and 45 paired ESCC tissues and corresponding para-cancerous tissues were measured using real-time quantitative polymerase chain reaction (qRT-PCR). The relationship between let-7 level and clinicopathological parameters in patients with ESCC was analyzed. Results The A value of let-7 in Eca109 cells transfected with let-7 was lower than negative control (P=0.005), while it was higher in Eca109 cells transfected inhibitor than that in negative control 72 hours after transfection. In comparison with negative control, the expression of let-7 in Eca109 cells transfected with let-7 was increased 33% (1.33 vs 1.00,P=0. 039) and it was decreased 50% in Eca109 cells transfected with inhibitor (0.50 vs 1.00,P=0. 014). The ratio of let-7 expression in ESCC tissue and para-cancerous tissue was 0.66 ± 0.47 with significant differece (P= 0.001). Moreover, The level of let-7 expression in Han patients with ESCC was lower than Kazakh patients with ESCC (0.48±0.43 vs 0. 88±0.51,P=0. 019). The level of let-7 expression in poorly differentiated ESCC tissue was lower than well differentiated ESCC tissue (0.42±0.30 vs 0.84±0.38,P=0. 015). The level of let-7 expression in patients with lymph node metastasis was lower than those without lymph node metastasis (0.50±0.35vs 0. 80±0.52,P=0. 032) . Conclusion It is demonstrated that let-7 can inhibit the carcinogenesis and development of ESCC. The level of let-7 expression is associated with cell differentiation,lymph node metastasis and nationalities.
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Objective To perform molecular cloning and sequencing, bioinformatics analysis,protein expression and function of extracellular signal regulated kinase (EgERK1) of Echinococcus granulosus in Xinjiang. Methods The specific primers of EgERK1 were designed and total RNA was extracted from Echinococcus granulosus in Xinjiang. EgERK1 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and prokaryotic expression plasmid pET28a-EgERK1 was constructed and sequenced. The sequences were analyzed by DNA sequencing and bioinformatics technology. The recombinant EgERK1 protein was induced and expressed. The biological function was detected using sodium dodecyl sulfate polyacrylamide gel electropheresis and Western blot. Results The sequence of RT-PCR product was 1125 bp, encoding 374 amino acids with isoelectric point of 6.34.This gene was a new ERK-homologues gene indicated by BLAST, named EgERK1(EU701008).Homology comparisons indicated that the homology of EgERK1 and EmMPK1from Echinococcus multilocularis was 95.45%, and was 43.04%-61.88% to ERK from Caenorhabditis elegans, S. cerevisiae, D. melanogaster and human. Phylogenetic analysis showed that EgERK1 clustered with EmMPK1. Bioinformatics analysis predicted that EgERK1 contained a highly conserved T-X-Y motif and activation loop segment of ERK-like kinase.Western blot results showed the EgERK1 recombinant protein could reacted specifically with anti-human ERK monoclonal antibody. Conclusion A new EgERK1 gene of Echinococcus granulosus is successfully cloned and its recombinant protein could reacted specifically with ERK1/2 antibody, which provides the basis for further study of EgERK1 function in the host-parasite interaction.
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Oxalic acid (OA) is inhibitory to many fungal plant pathogens. To further characterize the molecular mechanism of OA involved in fungal pathogenesis, OA insensitive mutants were screened from a chemical inducible Arabidopsis mutant library (about 6000 lines) using MS medium (calcium free) containing 1.2 mmol/L OA and 10 micromol/L estradiol. Harvested putative mutants were collected separately. Individual lines of mutants were screened again on modified MS medium containing OA. Mutants D33, D74, D154, D282 and D630 with enhanced OA resistance were obtained. The T-DNA flanking sequences were amplified by TAIL-PCR. The sequences were blasted against TAIR database. The result indicated that the T-DNA of mutant D33 was inserted between At2g39720 (zinc finger) and At2g39730 (Rubisco activase), and the T-DNA junctions of the other four mutants were the same, all inserted in the same site of the first intron of At5g10450 (14-3-3 protein GF14 lambda).